Edward h



No Model. E. H. WEATHERHEAD.

HYDRAULIC AIR PUMP.

No. 512,776 Patented Jan. 16, 1894 I /G J.

l 0 0 e I Z I. v

I g i I I A INvENTo 73 fi z L4 1' A Tito? NE'Y? EDWARD H. WEATHERHEAD, OF CLEVELAND, 01110, ASSIGNOR TO THE CLEVELAND FAUOET COMPANY, or SAME PLACE.

HYDRAULIC AIR-PUMP.

SPECIFICATION forming part of Letters Patent No. 512,776, dated January 16, 1894:.

Application filed June 1'7, 1892- Serial No. 4 7, No model- To all whom it may concern.-

Be it known that I, EDWARD H. WEATHER- HEAD, a citizen of the United States, residing at Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Hydraulic Air Pumps; and Ido hereby declare that the following is a full, clear, and exact description of theinvention, which will enable others skilled in the art to which it appertains to make and use the same.

Myinvention relates to hydraulic air pumps,

and is an improvement in the style or variety of pump shown and claimed in my applications .for Letters-Patent, filed, respectively, July 23, 1890, Serial No. 359,667, and October 22, 1890, Serial No. 368,938.

The invention consists in the construction and combination of parts substantially as shown and described and particularly pointed out in the claims.

The accompanying drawing showsa central vertical sectional elevation of my improved form of pump.

A represents the base of the pump, provided with the usual water passages,an'd water inlet a, and outlet or exhaust, a, and a main reciprocating valve, 0, and a controlling piston D therefor.

Secured to the base A is the main or outer cylinder E, and the inner cylinder F, having about half the length of the main cylinder, and closedat its top against the passages of water by suitably packing the said top against the inside of the outer cylinder. These two cylinders are so arranged with respect to one another that a water space is formed between them, and the inner cylinder is provided with a series of perforations e at its top .through which water enters into or passes from the said inner cylinde'r. The water space between these cylinders is in open communication with the source of supply, so that a constant head of water is maintained in this water space, and in the space above the returning piston within said inner cylinder.

G represents the main piston in the upper portion of the outer or main cylinder, and divides the said cylinder into air and water chambers, respectively, on its opposite sides. The upper portion of said cylinder or the vided at the top of the said tube or pipe IrI beneath the main piston G, and other openings, h, are formed in the bottom of the said tube or pipe H communicating with the space beneath the returning piston. By this construction a passage-way for the water is formed from the water spacein theinner cylinder beneath the piston K to the water chamber beneath the main piston G. I

As before stated, the pressure is constant above the piston K in the returning cylinder, and is on or off. in the main water chamber and the chamber beneath the returning piston in the inner cylinder, according to theposition of the main valve 0, and according as the pump is receiving or discharging water. If the parts be positioned as shown in the drawing, the pump is receiving water, and pressure is exerted against the bottom of the piston K and in the main water chamber upwardagainst the piston G. In all such cases the pressure above and below on the piston K is balanced, so that the full area of the piston G is utilized to force the said piston up and compress the air in the air chamber above it. When the main valve 0 is reversed so that the discharge passages o are open from within the inner cylinder beneath piston K and from themain water chamber through the piston rod Hthe upward pressure upon the said pistons of course is withdrawn, and the downward pressure of the water on the piston K forces said pistons down, and the dead water in the pump is expelled. This action continues until the position of the main valve is reversed, when live water again is admitted into the pump and the former action is repeated. In this easel employa continuous cylinder E within which are comprised all the several chambers hereinbefore referred to. This cylinder may of coursebei made of one or more.

sections, but there is no reason why it should not be made of a single piece, and this is the better construction. The main valve 0 is actuated by means of the pistonD when it is in thepositionishow-n inthe drawing, the greater area of said piston ofisetting the area of the said valve and the fluid pressure driving the said parts down together, as is now well-known in this art, and when this occurs the water dis-.

charges through the auxiliary valve from beneath said piston. To drive the said piston and valve up, water enters through the said auxiliary valve through the holes in the main casing and the holes in the neck of the valve and piston and, passing beneath the piston D, raises it. Thisoperation is old in the art.

Having thus described my invention, what I claim asnew, and desire to secure by Letters Patent; is-- 1. In awhydraulio air pump, the base provided with valve mechanism to control the inlet and the exhaust of the pressure fluid anda pair of concentric cylinders fixed to said base and theouter cylinder extending above the inner cylinder, and the inner cylinder watertight about its top against the outer cylinder, in combination with a main piston in; the upper portion of theouter cylinder and dividing the same into air and water'chambers, and a returning piston in the inner cylinder and a hollow tubeor pipe connecting said pistons through the top of the inner cylinder andlhavingflwater passages beneath each ofthe said pistons, substantially as described.

2. In a hydraulic air pump, a base provided with inlet and outlet passages and a controlling valve between said passages, an outer cylinder and an inner cylinder extending above said base and having a water space between them open to the source of supply, and open into the top of the inner cylinder,

in combination with a piston chamber and a piston in said chamber dividing said chamber into air and water chambers,a returningpistonin the inner cylinder and apiston rodhav- 

